Rear Brake Pad worn into Wedge Shape (2010 hatchback)

Just curious: are the "spreader springs" the V-shaped clips on the top of the pads? (1:53 in this video)

Good luck with this - wish I had some helpful advice but haven't done anything with the rear brakes yet (except lube the slide pins).
This previous thread may interest you though:
Seized rear left caliper | PriusChat

 

@Mendel Leisk will shortly be along and explain all. The twisted boot is a fabulous clue.

 

LOL, you know it...


@Nor'easter: Looking at the back of the pads (either one) is there a stubby protrusion:



Have you had the car since new; do you know it's brake service history (if any...)?

Just wondering if these are aftermarket pads, and don't have the pin. That pin, when properly seated between the spokes on the caliper piston face, will prevent it turning, which otherwise will happen, with every application of the parking brake.

Brake info in the attachment:

 

Well, it's not quite fair to call that a problem of the factory repair manual. What you found was probably the big PDF that kicks around on the web, which was made by a bunch of different people* doing 'print to file' of section after section of the manual from the web, without showing the window titles (which in the real online version is where you see what everlovin' section it is that you're looking at), and glomming them all together into one PDF with no contents, links, or navigation.

Text search is your only friend when trying to work with that sucker.

No such problems when using the real manual online (more info).

*you can tell because the online manual occasionally adds a page footer with the name of whoever was signed in to TIS and printed that page, and there are a bunch of different names in it, plus various whole sections came out with different margins, typefaces, etc.

 

What are you viewing it with? Acrobat Reader or full Acrobat, if you click on the book mark tab, if it's the pdf I have, you'll see:


Click this:

Then choose "Collapse...", and you'll be seeing:

A little neater. Yes, there's still broken links, but the terminology they use stays very consistant, so if you need to find one of those, as @ChapmanF says just searching for a text string will usually work.

If your pdf doesn't show bookmarks, pm me.

Getting back to your brake problem, this may or may not be the same issue as yours, but have a read:

I've had a beveled rear brake pad condition, but it was mainly the inside pad exhibiting bevelled wear, and I'm very familiar with the bozo who caused it.

The first time I pulled off the rear caliper, I cleaned the pads/shims, lubed the caliper pins and paid no attention to the caliper piston orientation when reassembling.

The caliper piston spokes (both sides) ended up riding up on aforementioned pins (intead of straddling them), creating a situation where all the pressure was bearing only that pin. Accordingly, my inboard side pads (the ones in contact with caliper piston) were severely worn at the ID, untouched at the OD. The inside face of the rotor was correspondingly about 50% rusty, from lack of pad contact.

I discovered this about 6 months after the first brake job, noticing scoring on the outside face of rotor, and excessive drag. I opened things up and found the beveled pads. I ended up getting new pads, removed and scoured the rotors, relubed everything and reassembling, taking special care to get the piston orientation right, like this:



It's imperative to have the piston thus. Then, to ensure it stays that way, doesn't jump:

1. Pump the brake pedal multiple times.
2. Spin the wheel, verify it's spinning "relatively" freely. The rear disk brakes have a modest amount of drag, but with a good push of the wheel it should continue to free-spin two or three more revolutions.
3. Lower car, reconnect 12 volt battery negative cable. (Good practice to disconnect for duration of brake work). Do not apply parking brake.
4. Take the car for a short test drive, using the brakes gently.
5. On return: apply/release the parking brake several times, raise the rear, verify wheels continue to spin semi-freely.

In my case, after doing the above remedial steps, the brakes sounded terrible, basically because the new pads were running over rotors that had zones untouched for that 6 months. I really thought I should have change the rotors as well. I hung in there, and in a week or so the rotors were "healed", back to quiet.

Wheel spin test:

 

Best wishes to you in 2020 too.

 

Out of curiosity, what do you mean by that exactly? Were the piston boots jacked or something?